18001

Check pressure transducer reading

Navigate to Diagnostics > PLC > Inputs/Outputs and monitor the pressure transducer input signal (typically DI configured in OB1 or FB for lubrication monitoring).

Compare actual pressure reading with machine data parameter for alarm threshold

Inspect distribution manifold

Physically examine the lubrication manifold and distribution blocks for visible blockages or hardened lubricant deposits at outlet ports.

Ensure machine is in safe state and lubrication pump is stopped before inspection

Clear blocked lines

Disconnect distribution lines at manifold and use compressed air or solvent to clear blockages, then reconnect and test system pressure.

Replace lubricant if contamination is suspected to prevent recurring blockages

Locate pressure relief valve

Identify the pressure relief valve in the lubrication circuit, typically mounted on the pump assembly or main distribution manifold.

Check machine documentation for relief valve pressure setting specification

Test relief valve operation

Manually actuate the relief valve (if equipped with manual override) or check if valve opens at specified pressure during pump operation.

Wear safety glasses as pressurized lubricant may spray when testing relief valve

Adjust or replace relief valve

If valve is adjustable, set to machine builder specification. If stuck or damaged, replace with identical part number and pressure rating.

After replacement, verify alarm threshold in PLC matches new relief valve setting

Verify transducer wiring

Check wiring connections at the pressure transducer and trace to the corresponding PLC input terminal, verify in Diagnostics > PLC > I/O status.

Use HMI Service screen to monitor real-time analog input value from transducer

Compare with mechanical gauge

Install a calibrated mechanical pressure gauge at the same point as the transducer to compare actual pressure with transducer reading displayed in SINUMERIK diagnostics.

Ensure gauge pressure rating exceeds maximum system pressure

Calibrate or replace transducer

If readings differ significantly, recalibrate transducer per manufacturer instructions or replace with identical specification unit and update scaling in PLC program if required.

Document new transducer calibration values in machine parameter backup

Access PLC program

Enter Service mode and navigate to PLC > Program > User Program to locate the lubrication monitoring function block or OB containing pressure alarm logic.

Search for alarm number 18001 or pressure monitoring variables in the PLC program

Review alarm threshold setting

Identify the pressure threshold parameter (typically stored in DB or M memory) and compare with machine builder specifications and actual operating pressure.

Only modify parameters with proper authorization and backup existing values

Adjust threshold parameter

Modify the pressure alarm threshold to appropriate value based on system design pressure plus safety margin, then download modified program to PLC.

Test new threshold by gradually increasing system pressure while monitoring alarm status